In conventional female connectors, the electric connector pieces are typically each formed into an elongated box. For example, as shown in FIG. 6, an electroconductive plate is bent into an electric connector piece 101 shaped as an elongated box provided with a lead terminal piece 101 at one of its longitudinal ends, and a pair of projecting tabs 103 and 104 formed in the mutually opposing strips 101a and 101b of the connector piece 101 in such a manner that one of the tabs 103 serves as a contact piece while the other tab 104 serves as a spring piece which elastically urges an electric male connector piece not shown in the drawing against the contact piece.
However, in such a conventional structure, since the contact piece 103 is integrally formed with the elongated, box-shaped electric connector piece 101, the whole electric connector piece 101 must be gold plated even though only the contact piece 103 is required to be gold plated, and the unnecessary gold plating leads to the increase in material cost.
In another conventional electric connector piece shown in FIG. 7, the connector piece 101 is constructed from a connector piece main body 105 having a C-shaped cross section, and a planar sheet spring piece 106. Securing tabs 107 provided in each upper edge of a pair of mutually opposing strips 105a and 105b of the connector piece main body 105 are crimped against the spring piece 106, and a contact tab 108 is bent from the connecting strip 105c of the connector piece main body 105. In this conventional structure also, since the contact tab 108 is integrally formed with the connector piece main body 105, the whole connector piece main body 105 having the C-shaped cross section must be gold plated, and the material cost tends to be high. Furthermore, crimping the securing tabs 107 against the spring piece 106 tends to reduce the manufacturing work efficiency.